Build: Update grunt-contrib-jshint

JSON needed to be added to JSHint globals as it's not implied by the es3
setting and yet all our supported browsers have it implemented.

(cherry-picked from 1556c4661af647e355a9a5c0a814012955e231bc)

package.json

@@ -29,7 +29,7 @@
     "grunt": "0.4.5",
     "grunt-cli": "0.1.13",
     "grunt-compare-size": "0.4.0",
-    "grunt-contrib-jshint": "0.10.0",
+    "grunt-contrib-jshint": "0.11.2",
     "grunt-contrib-uglify": "0.7.0",
     "grunt-contrib-watch": "0.6.1",
     "grunt-git-authors": "2.0.1",

src/.jshintrc

@@ -17,6 +17,7 @@
 	"wsh": true,
 
 	"globals": {
+		"JSON": false,
 		"jQuery": true,
 		"define": false,
 		"module": false,

test/.jshintrc

@@ -22,6 +22,8 @@
 		"require": false,
 		"define": false,
 		"DOMParser": false,
+		"JSON": false,
+		"Promise": false,
 		"QUnit": false,
 		"ok": false,
 		"equal": false,